如何让spring mvc web应用启动时就执行特定处理

Spring-MVC的应用中，要实现应用启动时就执行特定处理的功能，主要是通过实现下面这些接口（任选一，至少一个即可）

 

一、ApplicationContextAware接口

1 package org.springframework.context;2  3 import org.springframework.beans.BeansException;4 import org.springframework.beans.factory.Aware;5 import org.springframework.context.ApplicationContext;6  7 public interface ApplicationContextAware extends Aware {8     void setApplicationContext(ApplicationContext var1) throws BeansException;9 }

二、ServletContextAware 接口

1 package org.springframework.web.context;2  3 import javax.servlet.ServletContext;4 import org.springframework.beans.factory.Aware;5  6 public interface ServletContextAware extends Aware {7     void setServletContext(ServletContext var1);8 }

 

三、InitializingBean 接口

1 package org.springframework.beans.factory;2  3 public interface InitializingBean {4     void afterPropertiesSet() throws Exception;5 }

 

四、ApplicationListener<ApplicationEvent> 接口

1 package org.springframework.context;2  3 import java.util.EventListener;4 import org.springframework.context.ApplicationEvent;5  6 public interface ApplicationListener<E extends ApplicationEvent> extends EventListener {7     void onApplicationEvent(E var1);8 }

 

示例程序：

 1 package test.web.listener; 2   3 import org.apache.logging.log4j.*; 4 import org.springframework.beans.*; 5 import org.springframework.beans.factory.InitializingBean; 6 import org.springframework.context.*; 7 import org.springframework.context.event.ContextRefreshedEvent; 8 import org.springframework.stereotype.Component; 9 import org.springframework.web.context.ServletContextAware;10 import javax.servlet.ServletContext;11  12 @Component13 public class StartupListener implements ApplicationContextAware, ServletContextAware,14         InitializingBean, ApplicationListener<ContextRefreshedEvent> {15  16     protected Logger logger = LogManager.getLogger();17  18     @Override19     public void setApplicationContext(ApplicationContext ctx) throws BeansException {20         logger.info("1 => StartupListener.setApplicationContext");21     }22  23     @Override24     public void setServletContext(ServletContext context) {25         logger.info("2 => StartupListener.setServletContext");26     }27  28     @Override29     public void afterPropertiesSet() throws Exception {30         logger.info("3 => StartupListener.afterPropertiesSet");31     }32  33     @Override34     public void onApplicationEvent(ContextRefreshedEvent evt) {35         logger.info("4.1 => MyApplicationListener.onApplicationEvent");36         if (evt.getApplicationContext().getParent() == null) {37             logger.info("4.2 => MyApplicationListener.onApplicationEvent");38         }39     }40  41 }

 

运行时，输出的顺序如下：

1 => StartupListener.setApplicationContext
2 => StartupListener.setServletContext
3 => StartupListener.afterPropertiesSet
4.1 => MyApplicationListener.onApplicationEvent
4.2 => MyApplicationListener.onApplicationEvent
4.1 => MyApplicationListener.onApplicationEvent

注意：onApplicationEvent方法会触发多次，初始化这种事情，越早越好，建议在setApplicationContext方法中处理。